Networking and job hunting have come a long way in the last 20 years. New researchtools and the immediacy of theInternet bring job seekers directly in contact with companies and employers, allowing us to build networksthat our counterparts of the past would only envy.

LinkedIn continues to be the most direct and powerful online tool, one that’s certainly worth the energy if you’re job hunting. But be sure you don’t make one of the mostcommonLinkedIn mistakes: being passive about your search.

Setting up a profile and adding connections is a good start—but it’s just the beginning. To get the most benefit fromLinkedIn, you have to become a proactive user, reaching out to others, participating in the community, and continuously working to build your network.

Everyone knows the accidental “reply all” can be devastating, but there’splenty of harm in the intentional “reply all.” An E-mail reply that’s terse, caustic, or cryptic might make sense to a single recipient (who knows the writer well) but it rarely translates to a broad audience. A regular habit can leave coworkers with a negative impression that’s “almost irreversible,” says Sandy Allgeier, author of The Personal Credibility Factor: How to Get It, Keep It, and Get It Back (If You’ve Lost It).